This longitudinal study is designed to examine the role of biological, environmental, and psychological factors hypothesized to influence the relation between exposure to various types of violence and drug use. Participants include 400 adolescents representing two cohorts of teens living in high violence, impoverished urban areas. Latent growth curve models will be used to test specific hypotheses regarding the potential role of various factors as mediators and moderators of key variables influencing drug use in adolescents. In particular, coping processes and physiological responses to stress will be evaluated as mediators or moderator of associations between violence exposure and drug use. This home interview study is novel in that it examines both peer victimization and exposure to community violence, assesses activation of the locus cerulus/autonomic (sympathetic) nervous system and the limbic hypothalamic-pituitary-adrenal (LHPA) axis, and includes youth and parent assessments of emotion regulation skill and coping processes, including coping goals, threat appraisals, coping behaviors, and coping self-efficacy. The study follows a cohort of 200 5th graders, with limited exposure to drugs, and a cohort of 200 8th graders, with substantial exposure to drugs, over a 2-year period through key transitions into middle and high school. Thus, factors associated with both the initiation and exacerbation of drug use will be studied. This study will provide important information on the interaction of biological, environmental, and psychological risk factors for drug use. It has potential to reduce the tremendous societal costs of drug use by identifying behavioral and physiological correlates of inflation and escalation of drug use in adolescence. [unreadable] [unreadable] [unreadable]